DESCRIPTION
Forgot I had his on the counter "to do" pile. Various 5.7 ammo through the PR57. I had a user contact me that loads he was developing and using in his PR57 didn't translate well over to the M&P. I'm guessing the "locked"/rotating barrel action on the PR57 allows it to possibly hold pressure a little better? Necks are not pushed forward and the primers aren't showing all of the flatness that they did in the Sub2000 or P50.. Now if I could just get it to run. I'm sending the PR57 in along with the Sub2000. An member on AR15.com sent his in 3 times and finally got a bolt that holds the rim tight..